feat(expiry): 完成 #25 用户设置接口实现

internal/expiry/service.go

@@ -19,6 +19,7 @@ var (
 	ErrExpiryFilterCategoryInvalid = errors.New("category 参数无效")
 	ErrExpiryFilterSortInvalid     = errors.New("sort 参数无效")
 	ErrExpiryStatusInvalid         = errors.New("状态无效，仅支持 used/discarded")
+	ErrExpiryRemindDaysInvalid     = errors.New("remind_days 必须是 1-30 的整数，数量 1-5 个")
 )
 
 // Service 封装保质期模块业务逻辑。
@@ -86,6 +87,11 @@ type SummaryResponse struct {
 	Discarded    int `json:"discarded"`
 }
 
+// SettingsResponse 用户提醒设置返回结构。
+type SettingsResponse struct {
+	RemindDays []int `json:"remind_days"`
+}
+
 func NewService(repo *Repository) *Service {
 	return &Service{repo: repo}
 }
@@ -255,6 +261,41 @@ func (s *Service) UpdateItemStatus(id, userID uint, status string) error {
 	return s.repo.UpdateStatus(id, userID, status)
 }
 
+// GetSettings 获取用户提醒设置；若未配置则返回默认值。
+func (s *Service) GetSettings(userID uint) (*SettingsResponse, error) {
+	settings, err := s.repo.GetSettings(userID)
+	if err != nil {
+		return nil, err
+	}
+
+	if settings == nil || len(settings.RemindDays) == 0 {
+		return &SettingsResponse{
+			RemindDays: copyIntSlice(defaultRemindDays),
+		}, nil
+	}
+
+	return &SettingsResponse{
+		RemindDays: copyIntSlice(settings.RemindDays),
+	}, nil
+}
+
+// UpdateSettings 更新用户提醒设置。
+func (s *Service) UpdateSettings(userID uint, remindDays []int) (*SettingsResponse, error) {
+	validated, err := validateRemindDays(remindDays)
+	if err != nil {
+		return nil, err
+	}
+
+	settings, err := s.repo.UpdateSettings(userID, validated)
+	if err != nil {
+		return nil, err
+	}
+
+	return &SettingsResponse{
+		RemindDays: copyIntSlice(settings.RemindDays),
+	}, nil
+}
+
 func validateBaseFields(name, category string, quantity int, location, remark string) error {
 	name = strings.TrimSpace(name)
 	category = strings.TrimSpace(category)
@@ -367,3 +408,28 @@ func toItemView(item ExpiryItem) ItemView {
 		UpdatedAt:      item.UpdatedAt,
 	}
 }
+
+func validateRemindDays(days []int) ([]int, error) {
+	if len(days) == 0 || len(days) > 5 {
+		return nil, ErrExpiryRemindDaysInvalid
+	}
+
+	seen := make(map[int]struct{}, len(days))
+	result := make([]int, 0, len(days))
+	for _, day := range days {
+		if day < 1 || day > 30 {
+			return nil, ErrExpiryRemindDaysInvalid
+		}
+		if _, ok := seen[day]; ok {
+			continue
+		}
+		seen[day] = struct{}{}
+		result = append(result, day)
+	}
+
+	if len(result) == 0 || len(result) > 5 {
+		return nil, ErrExpiryRemindDaysInvalid
+	}
+
+	return result, nil
+}